Calculations of the Trapping Force of Optical Tweezers using FDTD Method

FDTD 방법을 이용한 광집게의 포획 힘 계산

  • Sung, Seung-Yong (Department of Mechatronics, Gwangju Institute of Science and Technology) ;
  • Lee, Yong-Gu (Department of Mechatronics, Gwangju Institute of Science and Technology)
  • 성승용 (광주과학기술원 기전공학과) ;
  • 이용구 (광주과학기술원 기전공학과)
  • Published : 2008.02.29


Optical tweezers are a tool that can use a tightly focused laser beam to trap and manipulate micron-sized dielectric particles that are immersed in a medium with lower refractive index. In this paper, the calculation of the trapping force of optical tweezers is presented. A nonparaxial Gaussian beam is used to represent a tightly focused Gaussian beam, and the FDTD (Finite-Difference Time-Domain) method is used for computing the electromagnetic field distributions in the dielectric medium. Scattered-field formulation is used for analytical expression of the incident fields. Using the electromagnetic field distribution from FDTD simulation, the trapping force is calculated based on Maxwell's stress tensor.


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